1. Field of Invention
The present invention relates to an air pump and pressure control devices thereof.
2. Description of Related Art
Air mattresses are used with cots and beds to provide yieldable body support. Motor driven pumps have been used to supply air under pressure to air mattresses. The biasing or firmness characteristics of an air mattress is determined by the pressure of the air in the air mattresses. The air mattress firmness can be varied by supplying additional air or venting air from the air mattress. Control mechanisms have been used to adjust the inflation of multiple separate zones of an air mattress. However, at least two different sets of pumps, air distributors and regulators are usually employed to control their respective zones' air pressures, thereby increasing lots of manufacturing costs. Therefore, even better and economic control mechanisms are needed in the endeavor for air mattresses.